MEKK2 KO DEFINES HEMATOPOIETIC CELL SIGNAL FUNCTION

本项目的目标是利用MEK激酶2 （MEKK2）的靶向基因破坏来确定其在造血细胞信号通路和基因表达调控中的作用。初步数据表明，在ES细胞衍生的肥大细胞中，MEKK2的缺失导致c-Kit和FcepsilonRI连接反应中JNK的激活缺失，并且受刺激细胞中某些细胞因子的产生显著减少。在T细胞/抗原呈递细胞偶联形成激活的T细胞中，MEKK2迅速易位到偶联界面。转染的激酶失活的MEKK2阻止偶联物的形成，并轻微抑制IL-4的产生。本项目的具体目的是生成MEKK2敲除小鼠，确定敲除表型，并收集小鼠的肥大细胞和T细胞，研究MEKK2缺失对信号通路、细胞增殖和细胞因子产生的影响。新的技术，如胚胎干细胞的体外分化和微芯片DNA阵列技术，将被使用。这些研究结果将对了解MEKK2在信号通路中的作用以及在细胞因子产生和免疫功能控制中的作用产生影响。它们还可能对癌症研究领域产生影响，因为T细胞中转染的MEKK2可以影响细胞周期的速度。最终，这些研究可能导致针对影响MEKK2活性的新疗法的发展，以治疗癌症或调节免疫功能。作为一名儿科血液学家、肿瘤学家，这个项目将非常宝贵地教会我在细胞信号传导、细胞生长控制和免疫学等领域的研究方法，这些领域都与我的研究领域密切相关。我的长期目标是应用这种增长和免疫学，所有与我的领域密切相关的领域。我的长期目标是运用这些知识来更好地理解导致信号通路失调并导致儿童癌症的细胞事件，从而设计出有效的靶向治疗方法。加里·约翰逊的实验室是学习这些技能的理想环境。

The goal of this project is to use targeted gene disruption of MEK kinase 2 (MEKK2) to determine its role in regulation of signaling pathways and of gene expression in hematopoietic cells. Preliminary date has shown that loss of MEKK2 in ES cell derived mast cells results in loss JNK activation in response to c-Kit and FcepsilonRI ligation and there is significantly decreased production of selected cytokines in the stimulated cells. In T cells with activation by T cell/antigen presenting cell conjugate formation, MEKK2 rapidly translocates to the conjugate interface. Transfected kinase inactive MEKK2 prevents conjugate formation and slightly inhibits IL-4 production. Specific aims of this project are to generate MEKK2 knockout mice, to determine the knockout phenotype, and to collect mast cells and T cells from the mice to study effects of loss of MEKK2 on signaling pathways, cell proliferation, and cytokine production. Novel techniques, such as in vitro differentiation of ES cells and microchip DNA array technology, will be used. Results of these studies will have an impact on the understanding of MEKK2's role in signaling pathways as well as its role in control of cytokine production and immune function. They could also have implications in the field of cancer research, since transfected MEKK2 in T cells can affect rate of cell cycling. Ultimately, these studies may lead to the development of novel therapies targeted at influencing MEKK2 activity to treat cancers or to modulate immune function. As a pediatric hematologist, oncologist, this project will be invaluable in teaching me research methods in the areas of cell signaling, control of cell growth, and immunology, all areas intimately involved with my field. My long term goal is to apply this growth, and immunology, all areas intimately involved with my field. My long term goal is to apply this knowledge to gain a better understanding of cellular events leading to dysregulation of signaling pathways and resulting in cancer in children, so that effective, targeted therapies can be devised. Gary Johnson's lab is an ideal environment in which to learn these skills.